<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			let stus=[];
			function load(){
				let xhr=new XMLHttpRequest();
				xhr.open("get","stu.xml",false);
				xhr.send();
				let data=xhr.responseXML;
				stus=data.querySelectorAll("student");
				document.querySelector("input").value=stus[0].getAttribute("sno");
				document.querySelector("input~input").value=stus[0].getAttribute("sname");
			}
			
			let index=0;
			function fun(){
				index=(index+1)%stus.length;
				document.querySelector("input").value=stus[index].getAttribute("sno");
				document.querySelector("input~input").value=stus[index].getAttribute("sname");
			}
		</script>
	</head>
	<body onload="load()">
		学号：<input type="text"/><br>
		姓名：<input type="text"/>
		<button type="button" onclick="fun()">下一个</button>
	</body>
</html>
